Ariana Grande and Liz Gillies became super close while working together on the set of Victorious, but they actually knew each other way before then. (They worked together on an episode of Battery's Down when they were just kids!)

Since these two gals have been friends for SUCH a long time, we're pretty sure that they've developed a forever kind of friendship. After all, they do everything together: they make YouTube vids, answer questions, take selfies... Liz was even in Ari's music video for "Right There"!

M rounded up 14 adorable pics of Ari and Liz that prove their friendship is forever. Do you have a best friend, too? Tell us all about her in the comments below!